This project is about creating a simple shell - your own little bash - and will give you a lot of experience with processes and file descriptors.
Table of Contents
Program name | minishell |
Turn in files | Makefile, *.h, *.c |
Makefile | NAME, all, clean, fclean, re |
Arguments | N/A |
External functs. | readline, rl_clear_history, rl_on_new_line, rl_replace_line, rl_redisplay, add_history, printf, malloc, free, write, access, open, read, close, fork, wait, waitpid, wait3, wait4, signal, sigaction, sigemptyset, sigaddset, kill, exit, getcwd, chdir, stat, lstat, fstat, unlink, execve, dup, dup2, pipe, opendir, readdir, closedir, strerror, perror, isatty, ttyname, ttyslot, ioctl, getenv, tcsetattr, tcgetattr, tgetent, tgetflag, tgetnum, tgetstr, tgoto, tputs |
Libft authorized | Yes |
Write a shell. Your shell should:
- Display a prompt when waiting for a new command.
- Have a working history.
- Search and launch the right executable (based on the PATH variable or using a relative or an absolute path).
- Not use more than one global variable. Think about it. You will have to explain its purpose.
- Not interpret unclosed quotes or special characters which are not required by the subject such as \ (backslash) or ; (semicolon).
- Handle ' (single quote) which should prevent the shell from interpreting the meta-characters in the quoted sequence.
- Handle " (double quote) which should prevent the shell from interpreting the meta-characters in the quoted sequence except for $ (dollar sign).
- Implement redirections:
- < should redirect input.
- > should redirect output.
- << should be given a delimiter, then read the input until a line containing the delimiter is seen. However, it doesn’t have to update the history!
- >> should redirect output in append mode.
- Implement pipes (| character). The output of each command in the pipeline is connected to the input of the next command via a pipe.
- Handle environment variables ($ followed by a sequence of characters) which should expand to their values.
- Handle $? which should expand to the exit status of the most recently executed foreground pipeline.
- Handle ctrl-C, ctrl-D and ctrl-\ which should behave like in bash.
- In interactive mode:
- ctrl-C displays a new prompt on a new line.
- ctrl-D exits the shell.
- ctrl-\ does nothing.
- Your shell must implement the following builtins:
- echo with option -n
- cd with only a relative or absolute path
- pwd with no options
- export with no options
- unset with no options
- env with no options or arguments
- exit with no options
Note: The readline() function can cause memory leaks. You don’t have to fix them. But that doesn’t mean your own code, yes the code you wrote, can have memory leaks